The principal objective of the Clinical Core will be to recruit and maintain a panel of approximately 400 volunteer patients and controls at the ADRC, and 100 volunteer patients and controls as part of our Hispanic initiative at our satellite clinic in Chula Vista. The Core will recruit new subjects with a diagnosis of Mild Cognitive Impairment (MCI) and very early AD (MMSE greater than or equal to 20) to replace subjects who have become more impaired. A pool of 40 subjects will be maintained with DRS scores greater than or equal to 109 to meet the needs of our research protocols. During this competitive renewal cycle we will specifically increase our pool of MCI subject to 100 for Dr. Bondi's project on functional MRI. Particular emphasis will continue to be placed on the recruitment of normal controls over the age of 80, in order to meet the need for greater numbers of autopsied brains for clinical-pathotogical correlations and biochemical studies. Annual participant evaluations will include demographic, history, medical neurological, psychiatric, and neuropsychological examinations to aid in the diagnosis and to track yearly changes in cognitive and neurological progression. The evaluations provide a behavioral database that can be used by the various research projects associated with the ADRC and in addition provide longitudinal data on the course and progression of AD. The Clinical Core maintains banks of DNA, plasma, serum, and CSF, used by various UCSD investigators and collaborators at other institutions and in industry. The Clinical Core provides the resources for participation in a variety of multi-center clinical trials and collaborative studies using both subjects and data. Finally developmental work will be undertaken to improve our ability to diagnose early AD and to improve the diagnosis of other dementias such as dementia with Lewy bodies and fronto-temporal dementia.